Part of the problem is that Canon ships the original software, then you install....then later you can download new updates from the Canon website BUT NOT the entire new software.
Technically... is not true, the updaters actually look for the product registry entries then install the new version overwriting the old one completely. I have seen this with EOS Utility, Canon Digital Photo Professional, Raw Codec, Style Editor. So I assume is the same with the rest.
I do not use original CD, just download the so called updates, make sure my registry has the entries in it, for example:
or, for Windows 64 bit:
and run the updater programs which install the full software.
just google around about "install canon software without cd" and you will find more details about this.
You need to remove EOS Utility completely from your PC - uninstall, then wipe file/folders if necessary.
Then download Canon EOS DIGITAL Solution Disk v25.2 from the web, it is available from numerous sources and is >270MB in size. Next do a proper clean install and not an update. That should work.
Not actually needed, just update if already installed